Such a feat is beyond the capabilities of the human body. To launch into powered flight using an elliptical wing and rise at a rate of around 2 m/s for five seconds for a 200lb load, we need to expend 1,900 watts continually. An Olympic athlete can expend, in short bursts, over 5,000 watts. An unfit layman (me) can do 2,300 watts in a short burst.

The thing is, our arms can't do it. They're shrivelled remnants of what they used to be. A chimpanzee has the upper body strength to literally rip your arm off. You wouldn't be able to do the same with one of his arms. Our legs are really powerful, but only work well in an alternating pattern, no good for flapping flight.

While a human powered aircraft is possible, we need to use our legs for it and a pedal system. Such a thing was done around twenty years ago, successfully. A chimpanzee would be able to sustain flapping bird-like flight with a correctly designed wing. Even if we mechanise it, and pedal a generator which actuates an ornithopter, we've added so much weight that you just get a silly spectacle on the ground.

Frankly, the whole "birdman" thing is ridiculous. Flapping flight is less efficient than a fixed wing is and a result of evolution having limbs to work with, not a wheel. Watch an albatross trying to take off (and failing hilariously) as opposed to a guy with a 5 hp lawnmower engine strapped to his back and a sail over his head.

Such a feat is beyond the capabilities of the human body. To launch into powered flight using an elliptical wing and rise at a rate of around 2 m/s for five seconds for a 200lb load, we need to expend 1,900 watts continually. An Olympic athlete can expend, in short bursts, over 5,000 watts. An unfit layman (me) can do 2,300 watts in a short burst.

There's no reason to doubt your scientific veracity, Hat - you've proven your chops long since - but I'm curious for citation regarding the above figures. I'm an avid cyclist, and in our hobby a rider who can generate 300w continuously is strong indeed. 400w continuous - double that plus some for bursts - is the province of pros, and the very best among them (Tour de France winners) can maintain 500w and burst at 1500w. Wattage output is an important metric in cycling training, and the measurement thereof has been refined to a high standard, so these numbers can be considered relatively accurate. Given the relative size of leg muscles, I can't imagine the combination of all other muscles (in the case of a swimmer, for instance) more than doubling leg output combined.

This reinforces the idea that human-powered flapping flight is not possible, of course - I'm in complete agreement - just wondering where your numbers came from. If accurate, it bodes well for me as a rider.

Such a feat is beyond the capabilities of the human body. To launch into powered flight using an elliptical wing and rise at a rate of around 2 m/s for five seconds for a 200lb load, we need to expend 1,900 watts continually. An Olympic athlete can expend, in short bursts, over 5,000 watts. An unfit layman (me) can do 2,300 watts in a short burst.

Can you show your work, please?

The amount of life needed is going to depend on the surface area of the wings as well as the rate of flapping.

Such a feat is beyond the capabilities of the human body. To launch into powered flight using an elliptical wing and rise at a rate of around 2 m/s for five seconds for a 200lb load, we need to expend 1,900 watts continually. An Olympic athlete can expend, in short bursts, over 5,000 watts. An unfit layman (me) can do 2,300 watts in a short burst.

Can you show your work, please?

The amount of life needed is going to depend on the surface area of the wings as well as the rate of flapping.

I'm guessing it was a simple potential energy calculation. The particular mechanical design simply determines the efficiency that gets factored in to make it even more infeasible.

Just doing the straight-up multiplication of 200 lb * 2 m / s gives just shy of 900 watts (using Google, here). So, that's not the entirety of Hat Monster's calculation. The kinetic energy of moving 2 m/s is 725 joules, so accelerating to that smoothly only adds another 145 watts. I don't feel like doing the calculation for 2 m/s as the average speed, from astanding start.

Frankly, the whole "birdman" thing is ridiculous. Flapping flight is less efficient than a fixed wing is and a result of evolution having limbs to work with, not a wheel.

While that may be true, there are also plenty of things (convenient for living organisms) that you can do with flapping wings that fixed wings just aren't good at. Some people (understandably) want to do those things, not just go "mechanical flying without a cockpit."

Quote:

Watch an albatross trying to take off (and failing hilariously) as opposed to a guy with a 5 hp lawnmower engine strapped to his back and a sail over his head.

Keep watching while the albatross soars close to set after set of waves while the guy with the lawnmower engine takes on water and drowns.

From an experience standpoint, wingsuit base jumping has been called the closest you can get to pure human flight. Technically it's not, of course... the wingsuit folks refer to it as 'falling with style'.

One of those things that I could watch for ages and wish I could do, knowing full well there's no way in hell I'd actually try it.

Frankly, the whole "birdman" thing is ridiculous. Flapping flight is less efficient than a fixed wing is and a result of evolution having limbs to work with, not a wheel.

While that may be true, there are also plenty of things (convenient for living organisms) that you can do with flapping wings that fixed wings just aren't good at. Some people (understandably) want to do those things, not just go "mechanical flying without a cockpit."

Quote:

Watch an albatross trying to take off (and failing hilariously) as opposed to a guy with a 5 hp lawnmower engine strapped to his back and a sail over his head.

Keep watching while the albatross soars close to set after set of waves while the guy with the lawnmower engine takes on water and drowns.

You're comparing millions of years of refinement of biological systems versus systems that have existed for little more than 100 years.

I'd like to see a guy with a lawnmower engine stay airborne for an entire year and circle the globe in 42 days.

Let's see, honeycomb all bones to decrease density, convert urea discharge to solid, install a myriad of wind sensors for precision movement of various wing control surfaces, obtain all water from fish you snatch out of the ocean on the fly, live on raw fish, have psychological makeup allowing for continuous flight, have long-range navigation system. Or use fish to power and lube lawnmower engine.

Watch an albatross trying to take off (and failing hilariously) as opposed to a guy with a 5 hp lawnmower engine strapped to his back and a sail over his head.

Keep watching while the albatross soars close to set after set of waves while the guy with the lawnmower engine takes on water and drowns.

In other words, the albatross and the lawnmower parasail are specialized for different things. Proving largely that both evolution and design select for traits appropriate for the task, and that few, if any organisms or devices are capable of doing everything well. I am not sure that this is a surprise.

That would be an interesting symbiosis... 2 pill-bug type of organisms that roll up, except for a leg from each one, which then attach to each other and form a self-driving axle? Or even a pair of shelled organisms on the beach or similar flat environment.

Are you suggesting that the evolution of man and subsequent inventions by man are a natural product of evolution?

Just seeking clarity here.

Evolution of man ... by definition ... is a natural product of evolution.

Inventions subsequent to the development of intelligence (and especially subsequent to the development of written language) are the product of a type of Lamarkian evolution; cultural and scientific insights are transferred from one individual to another by non-genetic processes.